Conventional thermosetting polymer (e.g. phenolic resin or epoxy resin) is usually used as electronic material for thermal isolation, insulation, anti-friction or high pressure resistance because of excellent mechanical and physical properties. For instance, epoxy resin is applied in Copper Clad Laminate (CCL) generally. However, conventional thermosetting polymer after solidification has some disadvantages such as embrittlement and mechanical strength deficiency.
In order to overcome the polymer disadvantages, those skilled in the art attempt to introduce inorganics having silicon-oxygen bond (Si—O bond) into polymer chain for property addition of inorganics and organics. For instance, polydimethylsiloxane (PDMS) is introduced into polybenzoxazine (PBz) to form a composite material which enables to improve PBz embrittlement and maintains PDMS flexibility.
Owing to aggregation phenomenon of inorganics in polymer, dispersibility and proportion of inorganics are not easy to be enhanced by physical dispersion such as sol-gel method, intercalation or delamination, and property addition of the composite material is limited. Oppositely, introducing inorganics into polymer chain directly by chemical bonding is able to relatively increase dispersibility and proportion of inorganics. For instance, introducing polyhedral oligomeric silsesquioxanes (POSS) into organic matrix is able to achieve molecular-level dispersion by polymerization between functional group of POSS and polymer chain.
POSS includes nonfunctional POSS, monofunctional POSS, difunctional POSS and polyfunctional POSS, and POSS structure is mainly composed of silicon-oxygen bond (Si—O bond), wherein silicon-oxygen bond with high bonding energy leads POSS possess excellent thermal stability. Difunctional POSS is able to be introduced into polymer chain backbone directly by cross-condensation to effectively decrease aggregation possibility of POSS and increase POSS proportion. POSS advantages are able to be introduced into organic matrix completely to improve polymer disadvantages. Therefore, those skilled in the art strongly develop difunctional polyhedral oligomeric silsesquioxane derivatives having high stability and synthesis thereof.